Adding 2 numbers

Shell Programming and Scripting
1

I would like to write a script with BASH to add two numbers (integer) and write the result to the standard output. Please help!

2

use the bc command or use awk.
assuming two numbers in a file called file1

cat file1 | awk ' printf("%d\n", $1 + $2)'

3

this short script works in sh & ksh, I assume bash as well.

let i=0
let i=$1+$2
echo $i
4

expr $var1 + $var2

5

There are loads of ways to do it.

Another is

echo "1 + 2" | bc

Matt

6

First of all, thank you very much for help, but I still have problems:

  • I have to write my script without bc or dc commands.

  • I would like to sum very-very big numers (600 characters long).
    It doesn't work with let, expr, or awk. (because of overflow)

Have you got any idea, how to solve this problem?

Thank you!

7

Just try Gawk!
It performs in superior to other awk's clones.

8 
echo "scale=600;1/7"|bc
.1428571428571428571428571428571428571428571428571428571428571428571\
42857142857142857142857142857142857142857142857142857142857142857142\
85714285714285714285714285714285714285714285714285714285714285714285\
71428571428571428571428571428571428571428571428571428571428571428571\
42857142857142857142857142857142857142857142857142857142857142857142\
85714285714285714285714285714285714285714285714285714285714285714285\
71428571428571428571428571428571428571428571428571428571428571428571\
42857142857142857142857142857142857142857142857142857142857142857142\
857142857142857142857142857142857142857142857142857142857